Numerous seeding implements are available for delivering seed from one or more central hoppers to individual row units. The individual row units may include a small hopper for automatic seed on demand refilling. When planting seed, certain agronomic benefits are available by changing seed varieties for a given row. For example, when planting seed corn the ability to easily select and change the pattern of rows for the male and female varieties can be highly advantageous. Many currently available bulk seed hopper systems are not readily compatible with planting practices utilizing two or more different seed hybrids.
Variety selection for the rows of a seeding implement is also advantageous for operations utilizing genetically modified seed. Planting of a refuge seed is often required when planting the genetically modified seed. A percentage of non-transgenic seed is typically planted with an insect transgenic seed to delay onset of resistance development. Regulatory agencies such as the USDA and EPA prefer the refuge crop be planted with a non-transgenic crop as a block separate and apart from the recombinant crops. Operators are required to purchase the regulatory amount of non-recombinant seed required for refuge along with any recombinant seed purchase. The percentage of refuge crop planted can vary from a small amount up to 20% or more of the total crop, depending on the type of crop plant subject to regulatory requirements and the amount of insect pressure expected for a particular geographic location. Although refuge for insect resistant hybrids can be planted adjacent the resistant crop or even in an adjacent field, effectiveness of the refuge increases if the refuge is planted in strips in the same field as the insect resistant variety.
In some fields, it may be desirable to vary the row location and/or percentage of refuge crop or other variety planted from one area to another. When a circle irrigated field is planted, for example, varying seed varieties can improve drought resistance for non-irrigated regions. Also, ability to change seed varieties within a field to improve pest or mold resistance can be highly advantageous. Changing varieties on the go or with little downtime has been difficult or impossible with many currently available seeding implements such as those with seed on demand delivery systems. As map-based farming practices become increasingly popular, the need for improved variety control for such delivery systems becomes more evident.
If the crop harvested from the genetically modified seed is to be separated from the crop harvested from the refuge seed, a different row pattern may need to be employed to accommodate harvester header configuration than if the crops are not to be segregated at harvest. Some farmers leave one unplanted row of crop approximately every sixty feet or other desired spacing to act as a row marker for spraying. The set-up of the planter or seeding implement for proper variety control, refuge percentage control, row spacing, marker row spacing and/or male-female seed row configuration can be very time-consuming. To achieve various row patterns, delivery lines to certain row units must be blocked or rerouted. Placement of hoppers for conveniently loading two or more materials while maintaining acceptable load distribution on the seeding implement with fully loaded hoppers is also a continuing source of difficulty. Loading of some of the seed varieties by hand from bags while bulk loading other varieties is not uncommon. Therefore, convenient access must be provided for both bulk filling and manual filling. It is also desirable to maximize use of individual hopper capacity to lessen the number of hopper reloading operations required.